Joseph Emile "Luc" Potvin was sentenced Friday to four years in prison for sex crimes involving a 17-year-old girl.

Potvin, 54, was a girls' volleyball coach in Dartmouth who worked with the Metro Lakers Volleyball Club, and also coached the girls' volleyball team at Prince Andrew High school in Dartmouth last fall.

Potvin was arrested at his home in Dartmouth May 13 after Halifax Regional Police received a complaint. The charges stem from offences committed between February and May of 2010.

He was charged with four sex-related charges — including one count of luring a child over the internet for a sexual purpose, one count each of sexual exploitation of a young person by a position of trust or authority, making child pornography, and sexual assault.

In court Friday, Potvin acknowledged he needed help.

"I do realize I have a problem and I would like to get a lot of help to deal with it in the short term and in the long term. Part of that, obviously, some of the things said by Dr. Kelln, where I need to make a better circle of friends with people my own age, which I've started to do. It's very important for the future."

Dr. Brad Kelln is the forensic psychologist Potvin's lawyer hired to review this case before sentencing.

After talking about the improvements he's trying to make in his life, Potvin then apologized.

"I'd like to apologize to the court for breaching the condition with my son. I'd like to apologize also to my family for putting them through this once more. Mostly to [the victim] and her family for what I've done."

Impact on victim

Judge Pam Williams said Potvin's actions made an impact on the girl's education.

"We have a young lady who because of this has struggled enormously with her schooling, both grade 11 and grade 12," Williams told Potvin. ""In one sense, Mr. Potvin, you've killed a part of [the victim] in a sense, her trusting nature, her youth."

Williams then told Potvin his four-year sentence didn't compare to what the victim will have to deal with for the rest of her life.

Potvin had almost daily contact with the teen for three months in 2010, most of it by cellphone or online, eventually escalating to direct sexual contact.

The girl's father had grown suspicious of the relationship, and one day he used the GPS feature on his daughter's cellphone to track her whereabouts. He tracked his daughter and Potvin to Sir Sanford Fleming Park — nowhere near where they were supposed to be.

The father then checked the computer and discovered hundreds of emails, text messages and video chats between Potvin and his daughter, according to the evidence.

The online conversations were sexually explicit and often one, or both of them were nude. From chatting online, things progressed to where Potvin and the girl had direct sexual contact.

The girl's father made copies of all the video chats, the emails and Facebook conversations recorded on his server and handed it all to police.

In 1999, Potvin was convicted of a sexual assault on a 12 year old girl. He received three years probation for that offence. He later obtained a pardon on his 1999 conviction, and that file was sealed until Sept. 14 of this year.